1. Field of the Invention
The present invention relates to an active energy beam curable composition and an ink which are excellent in storage stability and which are cured quickly.
2. Description of the Related Art
The active energy beam curable composition including, for example, ultraviolet light curable resins and electron beam curable resins has been hitherto used in many fields including, for example, inks, paints, adhesives, resists, and plate-making materials, by making the use of such a characteristic that the active energy beam curable composition maintains a liquid state in the dark, and the composition is cured when the composition is exposed to an active energy beam such as a light beam and an electron beam after being applied to an objective.
The active energy beam curable composition contains, for example, a photocation-polymerizable resin and a photocation polymerization initiator. The composition maintains the liquid state in the dark, because neither polymerization reaction nor cross-linking reaction occurs. On the other hand, when the composition is exposed to the light having a predetermined wavelength, then the polymerization reaction or the cross-linking reaction takes place, and thus the composition is cured.
Especially, when the active energy beam curable composition is used as an ink or a paint, a coloring agent such as a pigment is added. In this case, in order to improve the dispersion performance for the pigment or the like, a surfactant, which has a polar functional group (for example, an acidic functional group such as carboxyl group or a basic functional group such as amino group), is added.
The surfactant provides such an effect that the pigment dispersion performance is improved by making adsorption to the surface of the pigment by the aid of the polar functional group possessed by the surfactant.
However, when the surfactant having the polar functional group is added to the active energy beam curable composition, the storage stability of the active energy beam curable composition is deteriorated depending on the type of the surfactant. Consequently, for example, the active energy beam curable composition is cured in some cases, even when the composition is stored in the dark.
On the contrary, the curing performance of the active energy beam curable composition is deteriorated depending on the surfactant to be added. Consequently, for example, the active energy beam curable composition fails to cure sufficiently in some cases, even when the composition is exposed to the light after being applied to an objective.